No abstract available

No abstract available

No abstract available

[en] We demonstrate an experimental study on scaling mode instability (MI) threshold in fiber amplifiers based on fiber coiling. The experimental results show that coiling the active fiber in the cylindrical spiral shape is superior to the coiling in the plane spiral shape. When the polarization maintained Yb-doped fiber (PM YDF: with a core/inner-cladding diameter of 20/400 µ m) is coiled on an aluminous plate with a bend diameter of 9–16 cm, the MI threshold is ∼1.55 kW. When such a PM YDF is coiled on an aluminous cylinder with diameter of 9 cm, no MI is observed at the output power of 2.43 kW, which is limited by the available pump power. The spectral width and polarization extinction ratio is 0.255 nm and 18.3 dB, respectively, at 2.43 kW. To the best of our knowledge, this is the highest output power from a linear polarized narrow linewidth all-fiberized amplifier. By using a theoretical model, the potential MI-free scaling capability in such an amplifier is estimated to be 3.5 kW. (letter)

[en] Published in summary form only

[en] Full Text: Influence of γ-irradiation on Relaxor properties of TIInS₂< B> connection has been investigated. It was established, that in this connection Fog el-Filcher temperature T_f has been displaced aside low temperature, and Burns temperature T_d-aside high temperatures. In result the temperature interval of existence Relaxor conditions has been extended on-40K

[en] With the development of optical nanothermometry in biomedical sciences, it is urgent to develop near-infrared region (NIR) nanothermometers which could detect the temperature in deep tissue levels. In this study, NaYF₄:Yb,Er@NaGdF₄:Nd nanoparticles were successfully synthesized. The luminescence properties and the mechanism of formation of dumbbell morphology of NaYF₄:Yb,Er@NaGdF₄:Nd were investigated. As a novel optical nanothermometer, dumbbell-shaped NaYF₄:Yb,Er@NaGdF₄:Nd nanoparticles exhibited high sensitivity in the visible and NIR regions. These data seem to be promising in terms of expanding the optical detection range of non-contact fluorescence temperature sensors and satisfy the requirements for temperature detection in various biological tissues.

[en] The stability of charge ordered phases is doping dependent, with different materials having particularly stable ordered phases. In the half filled charge ordered phases of the cuprates this occurs at one eighth doping, whereas in charge-stripe ordered La_2−xSr_xNiO_4+δ there is enhanced stability at one third doping. In this paper we discuss the known details of the charge-stripe order in La_2−x Sr_xNiO_4+δ, and how these properties lead to the one third doping stability.

[en] Published in summary form only

[en] Highlights: • Diamagnetic susceptibility (DMS) of doped quantum dot is studied. • Hydrostatic pressure (HP) and temperature (T) affect DMS. • The dot is subjected to Gaussian white noise. • DMS also depends on mode of application of noise. - Abstract: We explore the diamagnetic susceptibility (DMS) of impurity doped quantum dot (QD) in presence of Gaussian white noise and under the combined influence of hydrostatic pressure (HP) and temperature (T). Presence of noise and also its mode of application discernibly affect the DMS profile. Application of HP and T invites greater delicacies in the observed DMS profiles. However, whereas the interplay between T and noise comes out to be extremely sensitive in fabricating the DMS profile, the pressure-noise interplay appears to be not that much noticeable. Under all conditions of temperature and pressure, the presence of multiplicative noise diminishes the value of DMS in comparison with that in presence of its additive analogue. The present study renders a deep insight into the remarkable role played by the interplay between noise, hydrostatic pressure and temperature in controlling the effective confinement imposed on the system which bears unquestionable relevance.